Resist sidewall angle impacts photoprocess performance on topography. For example, a sloped sidewall results in a large critical dimension (cd) change in a resist line going over a step in the substrate. Resist sidewall angle also impacts subsequent pattern transfer steps. For example, a sloped resist sidewall can result in a sloped sidewall in the etched material. Sometimes this is desirable, but often it is not.
It is desired to transfer a pattern, which is well-defined in the top surface of a material, more completely into the bulk of the material.